This invention relates to a ski with a bottom surface of synthetic plastic resin material having good sliding properties, which preferably consists of an appropriate polyethylene customary for bottom surfaces of skis and has, as an aid to climbing, a transverse profiling in the middle region of the length of the ski. "Transverse profiling" here denotes a non-planar design in which projections or recesses do not exclusively extend in the longitudinal direction of the ski but transversely, that is to say obliquely or at right angle to the longitudinal direction of the ski. The running surface of the bottom of skis of this type is normally smoothed, outside the transversely profiled region, by grinding in the longitudinal direction of the ski, using a sufficiently fine polishing material, so that the frictional resistance on these smoothed parts is as low as possible.
Hitherto, an optimum compromise between the sliding properties of the ski and its climbing properties could only be achieved by appropriate waxing of the surface. However, this is relatively expensive. Skis having aids to climbing in the form of transverse profilings are therefore increasingly used as cross-country skis - certainly when not participating in races. Above all, positively projecting scales, scales which have been negatively recessed from the synthetic plastics bottom surface or strips of skin are used for this purpose. Skis of this type are known, for example, from German Patent Specifications 273,954 and 1,059,327 or from German Offenlegungsschriften 1,678,261 and 1,954,075. Admittedly, these known climbing aids in most cases considerably improve the climbing properties of an unwaxed ski having a synthetic plastics running surface. If, however, the piste is very icy, the improvement in the climbing properties is slight. However, in most cases it is precisely under those conditions that good climbing properties are important. Moreover, for example, the positive scales generate unpleasant noises when going downhill. Finally, these known transverse profilings for skis brake too much in downhill running.